Herbicidal composition



Patented Dec. 1, 1953 HERBICIDAL COMPOSITION David T. Mowry and Ar'thurH. Schlesinger, Dayton, Ohio, assignors to Monsanto Chemical Company,St. Louis, ware No Drawing.

2 Claims. 1

Thepresent invention relates to herbicides and deals more particularlywith methods for the general destruction of undesired plants.

A number of herbicides are known, a variety of organic and inorganiccompounds having been suggested in the prior art for use asplant-killers. Among the disadvantages of known herbicides may bementioned corrosive effect on equipment, chemical reactivity with othercomponents customarily employed in agricultural sprays or powders,instability when exposed for long periods of time to ordinaryatmospheric conditions, and soil instability, e. g., chemical reactivitywith soil components and susceptibility to decomposition by soilmicro-organisms, which results in loss of the active material.

Now we have found that highly stable, noncorrosive herbicidalcompositions are obtained by employing as the active ingredient an alkylfurfurylidenecyanoacetate having the general formula in which R is analkyl radical of from 1 to 4 carbon atoms. As examples of compoundshaving the above general formula may be mentioned methylfurfurylidenecyanoacetate, isopropyl furfurylidenecyanoacetate, n-butylfurfurylidenecyanoacetate, etc. The alkyl furfurylidenecyanoacetates arereadily obtainable in known manner by reaction of furfural with theappropriate alkyl cyanoacetate in the presence of an alkaline condensingagent.

The present alkyl furfurylidenecyanoacetates are effective herbicidesover wide ranges of concentrations. Their effectiveness may be measuredby determining the inhibition of root growth as compared to similaruntreated plants.

The general usefulness of a herbicide may be measured by comparing theconcentrations of a herbicide required to produce a certain inhibitionof growth on a broad-leafed plant with the concentration of a herbiciderequired to produce the same inhibition of growth on a narrowleafedplant. For evaluation in many laboratories the cucumber has been adoptedas a typical broad-leafed dicotyledonous plant for technical reasons,and wheat has'been used as a standard narrow leafed monocotyledonousplant. The general technique of evaluation of herbicides by growingseedlings in petri dishes has been described by Thompson, Swanson andNorman, Botanical Gazette, 107, 476-507 (1946),

Mo., a corporation of Dela Applicatioii January 25, 1951, Serial No.207,853

Example I Herbicidal activity of several alkylfurfurylidenecyanoacetates wasdetermined by germination of cucumberseeds .for l daysat a temperature of 76 F. in the presence of aqueoussuspensions of each of the indicated chemicals at concentration of 100p. p. m. Seventy-five seeds were used for each test. The results areexpressed as per cent length of the primary roots in the presence of thechemical compared with the length of the primary roots of controls whichhad been germinated in water. The activity of isopropyl carbanilate, astandard herbicide, as determined by the same test is included forcomparison.

Penfilnt grow at Compound tested 100 parts per million Methyliurfurylidenecyanoacetate 12 Ethyl furfurylidencyanoacetate l2 Isopropylcarbanilate 14 Percelalnt grow at Compound tested 100 parts per millionFuriurylldenecyanoacetamide 85 Furfurylideneacetone 76 Diethylfurfurylidenemalonate 83 E yl a, 4-dlcyanocinuamate Ethyla-cyano-p-chlorocinnamate Herbicidal compositions containing the presentester compounds may be oil solution or an oil emulsion of the estercompound. The oil solutions may be obtained simply by dissolving theester compound in oil in effective proportions In most instances,however, it is more expedient to prepare oil concentrates of the esterconcentrate, which oil concentrates are diluted by the consumer prior totheir use. Dilution of the oil dusts; or they may be used withwater-insoluble insecticides, fungicides, etc, in.. customarily em-.-ployed organic solutions.

The aqueous suspensions: may bee used; to

destroy already existing plant growth by direct application to theundesirablaplants or they may be employed to prevent the plant growthapplication to soils. When employed to prevent plant growth, for examplein parking: areas; highway abutments, railway yards, etc., they may beapplied. eithen as an: aqueous spraw or:- dust or they maybe:a'dmixed:wlthz customarilseem: ployed temporary surfacingmaterials,e. g., oils, cinders, etc. The present invention thus pro-- vides a:generally: usetuli method? o1:- preventing and? destroying?undesirable!- pl'ant growth; I

There: may: be? employedi 0111 part: to 20I parts of the alkylfurturylidenecyanoacetate per hundred parts by weight of the carrier,and in this manner an acre of land may be freed of plants by applicationof only a few pounds of the present herbicides.

What-we claim-is:

l. The methodcof destroying, undesired plants which comprises applyingto said plants a toxic quantity of a herbicidal composition comprisingmethyl furfurylidenecyanoacetate as the active ingredient;

2. The-methodioi, destroying undesired plants which comprisestapplyingto said plants a toxic quantityof, an; aqueous suspension of methylfurfurylidenecyanoacetate.

DAVID T. MOWRY. ARTHUR H. SCHLESINGER.

References Cited in the file of this patent UNITED STATES PATEN'ISNumber: Name" Date;

2,435,780 Heals Feb, 10, 1943.

OTHER; REFERENCES.

Beilstein", Handbuch .der Organi'schen Chemie;v

4th Edition vol; XVIII, ,page: 33 8:- (1934)

1. THE METHOD OF DESTROYING UNDESIRED PLANTS WHICH COMPRISES APPLYING TOSAID PLANTS A TOXIC QUANTITY OF A HERBICIDAL COMPOSITION COMPRISINGMETHYL FURFURYLIDENECYANOACETATE AS THE ACTIVE INGREDIENT.